[dba-Tech] Nations, City States, mapping same, etc.

Fortunately, there is a DB design question herein, else I'd have to post it
on the OT list, which is way too noisy for me LOL.

I was under the impression that Singapore was a city-state, but I googled a
few things and discovered that it is considered a nation. Further, said URL
(http://www.cia.gov/cia/publications/factbook/geos/sn.html) contains a very
interesting set of columns, but I will confine this question to the set
titled "Government", which includes:

Country Name:
	Long form: Republic of Singapore
	Short form: Singapore
Government Type:
Capital: Singapore
Administrative Divisions:
Independence:
National Holiday:
Constitution:
Legal System:
Suffrage:
Executive Branch:
Judicial Branch:
Legislative Branch:
Political Parties and Leaders:
Political Pressure Groups and Leaders:
International Organization / Participation:
Diplomatic Representation from the U.S.:
Flag Description:

(Fill in the blanks by visiting the URL above.)

My questions are: 

1. Is Singapore a city, a nation-state or a nation? 
2. Are these terms obsolete? 
3. Was Singapore declared a nation simply so it could fit conveniently into
the database?
4. Are there any other cities to which we might ascribe the descriptor
"city-state"? (Or do we fold all such potential candidates into "nations" as
this database does with Singapore?)
5. Are there any parts of the nation of Singapore which are not parts of the
city Singapore?
6. Prior to 1999, how was Hong Kong classified? (And currently, how is Macao
classified?)
7. Prior to reunification, what was the status of Berlin?
8. In post WWII, what was Vienna (c.f. "The Third Man", directed by Carol
Reed and starring Orson Welles and Joseph Cotton)? A city-state? A city
controlled by four armies? A remnant of pre-war Austrian glory?

Opinions and references most welcome! And just to ensure that this stays in
the DB realm, until now I have been using the ISO list of nations. Perhaps I
should expand my list of columns to include all these other attributes?

TIA,
Arthur